The present invention relates to pressure gauges, and more particularly to a gauge having a modular construction that enables it to be adapted to sense pressure and/or temperature over relatively wide ranges with the use of a relatively low pressure transducer that produces a highly accurate digital output signal.
In the past, the measurement of pressure or temperature over different ranges has required different types of sensing gauges with varying degrees of accuracy. For example, relatively low pressures can be measured with mechanical or electrical transducers that are low cost and have high accuracy. However, when high pressures are to be measured, such as those that are encountered at a well head during oil drilling operations, it is necessary to utilize more expensive high pressure transducers that are less accurate. Sometimes the initial pressure that is encountered at a well head is so high that even the capacity of presently available state of the art high pressure transducers is exceeded.
At the other extreme, the measurement of relatively small changes in pressure or the measurement of very low pressures also requires transducers that are quite expensive.
Consequently, in situations where it is necessary to measure different pressures, wherein each pressure might be in a range that is substantially different from that of the other pressures, it is necessary to have on hand a variety of different types of transducers, each of which might have a different degree of accuracy, and some of which may be quite expensive.